1. Field of the Invention
This invention relates to the intrusion alarm art, and more particularly, to a security panel arrangement usable in intrusion alarm systems to secure surface portions of a structure from unauthorized breach.
2. Description of the Prior Art
Alarm systems for warning of unauthorized intrusion into a structure are most commonly designed to detect the unauthorized opening or removal of the doors or windows of the structure. However, in many situations entry may also be had by breaking into the structure without opening a door or window. Many walls, hollow core doors, wooden floors, skylights, and air ducts, for example, are easy prey for a thief or other unauthorized intruder. Alarm systems which monitor only the opening of doors and windows can thus be circumvented.
The only intrusion alarm systems known to me which are triggered by an intruder breaking through a wall or a door itself involve lacing the surface to be secured with a continuous wire or other conductor. The conductor is then connected to a mechanism designed to monitor its continuity and to produce a warning signal when the continuity is broken. The wires in these systems are fastened directly to the surface to be secured.
Such arrangements have many drawbacks when applied to surfaces such as walls and doors. Initially, they are quite expensive to install due to the high labor cost of manually applying the conductor to the surface in a desired pattern. The lacing operation should be performed by a qualified electrician capable of calculating the resistance of the overall system by taking into account the length of wire, the pattern in which it is applied and the number and type of joints used. The wire must also be skillfully applied to avoid an increase in electrical resistance which results from straining the wire. The resulting configuration is then completely exposed to damage from physical contact therewith and to possible circumvention thereof by an intruder having access to the interior of the structure prior to his planned intrusion. The exposed wires are also subject to deterioration from exposure to the elements and are unsightly in many contexts.
It is therefore desirable in many applications to provide a security device which may be applied to the walls and other surfaces of a structure to monitor unauthorized breach thereof and which may be inexpensively applied and be protected from physical damage and deterioration. The device should also be visually undetectable when installed, if desired.